On Lake General Carrera, the body of water that spans the Chile-Argentina border, a peninsula of solid rock juts out towards the lake's center. The rock's exterior — warped, unimpressive stone, cut with ugly foliage — is perversely deceiving. Like a gemstone, its innards house an unexpected, ethereal surprise.

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The peninsula doesn't sit deadpan on the water — propped up on rock pillars, formed by 6,000 years of waves slapping up against calcium carbonate, the underside has eroded into a series of solid, psychedelic marble caves.

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Carved out of the Patagonian Andes mountain range, the cosmic caves (known colloquially as the Cuevas de Mármol) are one of Chile's greatest tourist attractions. Being inside the Cuevas de Mármol is like seeing Alaska's Aurora Borealis projected onto a ceiling — undulating colors of teal, yellow, purple and green make up one of nature's finest masterpieces.

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The caves, however, aren't easy to find. Without an accessible path, the only way to the marble city is by boat. Visitors can take a ferry from Chile Chico or rent kayaks on calm days to explore the caves' tunnels.

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Unfortunately, a plan to build a dam close to the Cuevas de Mármol has threatened the peninsula's remoteness, so if you're planning on visiting, you might want to do it soon. Take photos for us, will you?

[h/t Travel and Leisure